Example embodiments of the inventive concepts relate to a one-way nut fastener, and in particular, to a one-way nut fastener capable of preventing a nut from being loosened from a gas pipe line to prevent a gas leak from the gas pipe line by an operator's mistake.
In a semiconductor fabrication plant, there are many pipe lines to deliver process gases. Since some of such process gases are toxic and flammable, an accident such as gas leak causes severe and dangerous environmental pollution. The gas leak accident may be caused by vibration of the pipe lines, when a pipe fitting loosely fastened by a nut is used to connect the pipe lines to each other. In addition, the gas leak accident may also occur when an operator turns to loosen the nut of the pipe fitting by mistake.